1. Field of the Invention
The present invention relates to an image displaying apparatus and, in particular, to an image displaying apparatus, which projects a light beam having information on an image generated by an image generator onto the eyes of an observer through an optical system and displays the image as a virtual image for an observer.
2. Related Background Art
Conventionally, a large-screen image, which produces presence is displayed by using a large CRT display system, a projection TV or the like.
These systems, however, have problems of restricted conditions for use. For example, they require larger space and the images are difficult to see unless surrounding thereof is dark. For this reason, there has recently been proposed an apparatus designed to directly project a light beam from an image displayed on an image display device onto the eyes of an observer through an optical system disposed extremely close to a person's face, thereby making the observer visually recognize an equivalently larger image as a virtual image.
FIG. 1 illustrates a main portion of an image displaying apparatus proposed in Japanese Patent Application Laid-Open No. 4-34512. An image is displayed on a liquid crystal display 101 by data sent through a signal line 116. The display 101 is transmissively illuminated with a backlight light source 104. Light which has passed through the display 101 provides a light beam including the information of the displayed image.
After the light beam passes through a magnifying lens 151, it is reflected by a mirror 150 to become a light beam 109 and thereafter it reaches a pupil 107 of an observer. The observer visually recognizes the displayed image by observing the light beam 109. The power of the magnifying lens 151 is set so that an image on the liquid crystal display 101 is displayed as a virtual image at a predetermined distance, e.g., at a point, which is 5 meters in front.
In the foregoing conventional example, however, a surface whereon the virtual image is displayed is a plane; therefore, the displayed image seems flat for the observer, failing to display to produce greater presence. Moreover, when the image display of the foregoing conventional example is applied for displaying an image of a virtual reality system, the image gives the observer an impression as if the image were projected on a flat screen, failing to produce a satisfactory presence.